Insomniac is one of the developers that Sony could previously count itself fortunate for having in its corner. For the past 14 years, the developer has worked exclusively on games for the PlayStation brand, most notably, Ratchet and Clank and Resistance .

Now Insomniac has signed a deal with EA Partners to develop for the Xbox 360 as well as the PS3. 

Insomniac told Gameinformer that ““Our commitment and our relationship with Sony continues, and it’s as strong as ever — as is our commitment to Ratchet and Resistance. We will continue making games with Sony…. The relationship remains great.” 

Sony also seems pretty cool about the development, saying “Sony Computer Entertainment and Insomniac Games will continue to build upon a strong, successful 14-year partnership that has led to more than 35 million games sold and enjoyed by fans around the world. We look forward to unveiling Insomniac’s next PS3 exclusive properties in the near future.” 

Ratchet and Clank and Resistance will continue to be Sony exclusives. 

It would seem that Insomniac is planning to set up a third development process to handle its new responsibilities alongside its existing ones.